Avalanche: Summit

Location: Tenderfoot

Route & General Observations

Ascended to 2400 feet on the standard Tenderfoot up-track. Above ~1700 feet on this tour we experienced a very unstable snowpack and what we’d deem considerable avalanche danger. Both our party and another party experienced significant whumpfing. Previous natural avalanches were observed on Tri Tip, Tenderfoot, Fresno Ridge, and Butch.

Avalanche Details
If this is an avalanche observation, click yes below and fill in the form as best as you can. If people were involved, please provide details.
Trigger NaturalRemote Trigger0
Avalanche Type UnknownAspect Unknown
ElevationunknownSlope Angleunknown
Crown DepthunknownWidthunknown
Vertical Rununknown  
Avalanche Details

Several natural avalanches occurring most likely on Friday, Dec 8th, were observed including:

Fresno Ridge: Small loose snow - D1
Butch: Several paths have run with several piles of debris seen in gullies (One of these noted by Alex McLain Friday Dec 8th).
Tri Tip: D1.5 on the NW shoulder mid slope, D1-D2's on Northerly aspects
Tenderfoot: 1-2' slab that fractured but did not fully release on lower standard descent route at 2400 ft

Red Flags
Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.
Obvious signs of instability
Recent Avalanches?Yes
Collapsing (Whumphing)?Yes
Cracking (Shooting cracks)?Yes
Observer Comments

Significant and visible collapsing/whumpfing in clearings on ascent that resulted in a wave in the snow surface as trees shook off snow. Abundant whumpfing reported by another party.

Weather & Snow Characteristics
Please provide details to help us determine the weather and snowpack during the time this observation took place.

1230 @ trailhead: OCT, 37 F @ 1300 ft, no precip, calm winds
1500 @ snow pit: OCT, mid 30s @ 2300 ft, S-1 rain, light winds
1600 @ trailhead: OCT, 38 F @ 1300 ft, no precip, calm winds

Snow surface

Melt freeze crust that transitioned to moist new precip particles around 2200 ft. Melt freeze crust was 3 cm thick near trailhead (rain Friday) growing to softer 5 cm thick higher up (wet snow/rain Friday). This melt freeze crust made for challenging skiing conditions. Grass poked through in clearings in patches. Early season conditions persist. The rain/snow line from Friday's precip was above our high point and estimated at 2,600', possibly higher.


Numerous hand pits failed on isolation on faceted snow sitting over a melt freeze crust near the ground.

ECTP 11 down 40 cm on 1-2 mm facets (facet layer was 10 cm thick) over a melt freeze crust. Elevation 2300 ft, WNW, 22 degrees

Photos & Video
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